DET21

Directly heated high-power triode for transmitting and RF service; available source material does not establish a narrower application confidently.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: -
Base pins: -
Nominal heater: 10 V / 5.5 A

Description

Low-frequency thoriated-filament carbon-anode triode for Class-A/Class-B audio amplifier and modulator service.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: -
Base pins: -
Nominal heater voltage: 10 V
Nominal heater current: 5.5 A
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

1 physical section, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 2800 Ω
Transconductance: 0.0045 S
Amplification factor: 12.5
Max plate voltage: 3000 V
Max plate dissipation: 125 W

Applicable promoted ratings mapped semantically from the printed approximate-data/ratings tables; useful non-promoted operating, capacitance and service data retained in TUBE_SECTION_PARAMETER.

Source-dependent data

Operating conditions by source

Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.

Data set 01

1955 Marconi

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Plate Resistance
2800 ohm
Anode-Grid Capacitance
18.25 pF
Anode-Cathode Capacitance
10.3 pF
Grid-Cathode Capacitance
10 pF

Characteristic

Intended Service
Class A or Class B audio amplifier/modulator